Hand-washing

This is hilarious. Hand-washing apparently has profound psychological effects, which are usually purported to be metaphorical (“Out, damn’d spot!”). But this leaves me dying for experimental clarification -what happens to the postdecisional dissonance if the subjects instead:

1) “wash” their hands in some staining, sticky, or malodorous substance?

2) are told (prior or post ablution) that the soap was contaminated with some pathogen, so they need to wash again to be safe?

BREVIA

Washing Away Postdecisional Dissonance

After choosing between two alternatives, people perceive thechosen alternative as more attractive and the rejected alternativeas less attractive. This postdecisional dissonance effect waseliminated by cleaning one’s hands. Going beyond priorpurification effects in the moral domain, physical cleansingseems to more generally remove past concerns, resulting in ametaphorical “clean slate” effect.

Hand washing removes more than dirt—it also removes theguilt of past misdeeds, weakens the urge to engage in compensatorybehavior (1), and attenuates the impact of disgust on moraljudgment (2). These findings are usually conceptualized in termsof a purity-morality metaphor that links physical and moralcleanliness (3); however, they may also reflect that washingmore generally removes traces of the past by metaphoricallywiping the slate clean. If so, washing one’s hands maylessen the influence of past behaviors that have no moral implicationsat all. We test this possibility in a choice situation. Freelychoosing between two similarly attractive options (e.g., Parisor Rome for vacation) arouses cognitive dissonance, an aversivepsychological state resulting from conflicting cognitions. Peoplereduce dissonance by perceiving the chosen alternative as moreattractive and the rejected alternative as less attractive afterchoice, thereby justifying their decision (4,5). We test whetherhand washing reduces this classic postdecisional dissonanceeffect.

In individual sessions as part of an alleged consumer survey,40 undergraduates browsed 30 CD covers as if they were in amusic store. They selected 10 CDs they would like to own andranked them by preference. Later, the experimenter offered thema choice between their fifth- and sixth-ranked CDs as a tokenof appreciation from the sponsor. After the choice, participantscompleted an ostensibly unrelated product survey that askedfor evaluations of a liquid soap; half merely examined the bottlebefore answering, whereas others tested the soap by washingtheir hands. After a filler task, participants ranked the 10CDs again, allegedly because the sponsor wanted to know whatpeople think about the CDs after leaving the store (6).

Can washing one’s hands attenuate the need to justifya recent choice? Yes (Fig. 1). For those who merely examinedthe soap, the preference for the chosen over the rejected alternativeincreased from before choice [mean (M) = 0.14 and SD = 1.01]to after choice (M= 2.05, SD = 1.96) by an average of 1.9 ranks[F(1, 38) = 20.40,Pthe standard dissonance effect. In contrast, for those who washedtheir hands, preferences were unaffected by their decision [beforechoice,M= 0.68, SD = 0.75; after choice,M= 1.00, SD = 1.41;Freduced the need to justify one’s choice by increasingthe perceived difference between alternatives [F(1, 38) = 6.74,P= 0.01, for the interaction of time and hand-washing manipulation].

A study with a different choice task, cleaning manipulation,and measure replicated this finding (7). In individual sessions,85 students responded to an alleged consumer survey about fourfruit jams (shown in pictures). They were subsequently offereda choice between two jars as a sign of the sponsor’s appreciation.After their choice, participants completed an ostensibly unrelatedproduct survey about an antiseptic wipe; half merely examinedthe wipe, whereas others tested it by cleaning their hands.Next, they rated the expected taste of the four jams (0 = notgood at all; 10 = very good).

These findings indicate that the psychological impact of physicalcleansing extends beyond the moral domain. Much as washing cancleanse us from traces of past immoral behavior, it can alsocleanse us from traces of past decisions, reducing the needto justify them. This observation is not captured by the purity-moralitymetaphor and highlights the need for a better understandingof the processes that mediate the psychological impact of physicalcleansing. To further constrain the range of plausible candidateexplanations, future research may test whether the observed“clean slate” effect is limited to past acts that may threatenone’s self-view (e.g., moral transgressions and potentiallypoor choices) or also extends to past behaviors with positiveimplications.